<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <script>
            let arr=["来抓我呀","抓不到吧","急不急","急死你","我又溜了"];
            let index=1;
            function f1(){
                let btn=document.getElementById("btn");
                // [0.0,1.0)之间的随机小数
                btn.style.left=Math.random()*1000+"px";
                btn.style.top=Math.random()*600+"px";
                // 1  2  3   4   5   6  7  8 9  10  11

                btn.value=arr[index++ % arr.length];
            }
        </script>
    </head>
    <body>
        <input type="button" value="来抓我呀" id="btn" style="position: relative;top:100px;left:100px;" onmouseover="f1()">
    </body>
</html>